Stomach pain and cramps when peeing, gastric problem. What is cause and treatment?

I have stomache pain and cramps when I use the bathroom and I have pain in my left pelvic area. I thought maybe because It was due to PMS, but i notice this happens every time I go to my family's Mexican party. The food is made from scratch. We eat mole sauce, enchiladas, and ponche drink. its good stuff but the next day i start feeling pain in my pelvic side and gas. What can I do to get rid of this pain? Its been 2 days now!